Electrical and optical properties of hydrogen plasma treated β-Ga2O3 thin films

Abstract The behavior of H in β -Ga 2 O 3 is of substantial interest because it is a common residual impurity that is present in β -Ga 2 O 3 , regardless of the synthesis methods. Herein, we report the influences of H-plasma exposure on the electric and optical properties of the heteroepitaxial β -Ga 2 O 3 thin films grown on sapphire substrates by chemical vapor deposition. The results indicate that the H incorporation leads to a significantly increased electrical conductivity, a greatly reduced defect-related photoluminescence emission, and a slightly enhanced transmittance, while it has little effect on the crystalline quality of the β -Ga 2 O 3 films. The significant changes in the electrical and optical properties of β -Ga 2 O 3 may originate from the formation of shallow donor states and the passivation of the defects by the incorporated H. Temperature dependent electrical properties of the H-incorporated β -Ga 2 O 3 films are also investigated, and the dominant scattering mechanisms at various temperatures are discussed.